China has acted swiftly and severely in punishing those it accuses of sparking bloody separatist Muslim riots in the troubled western province of Xinjiang. After a public sentencing rally attended by 5,000 people in Yining city, three men were executed and 27 others jailed, a move which one exiled Uighur nationalist organisation immediately warned would prompt further protests.

The sentencing and executions took place last Thursday, but details only became available at the weekend. They are the first sentences to be handed down following a series of violent attacks this year by Uighur nationalists against Chinese rule. The Yining riots, which in early February killed nine people and injured 200, were followed by bus bombings later that month in the Xinjiang provincial capital of Urumqi, killing nine and wounding 74.

A subsequent bus bomb blast in Peking was also presumed to be the work of Muslim separatists.

All those charged in Yining were ethnic Uighurs, a Turkic-speaking Muslim nationality which for decades has sporadically attempted to throw off Chinese rule and set up an independent "East Turkestan" state.

As well as the three executions, one man was sentenced to life in prison and 26 were given jail terms ranging from 7 to 18 years, said the Xinjiang Daily, describing them as the first batch of rioters to be sentenced.

While few Uighurs probably support indiscriminate bus bombings by the separatists, anti-Chinese sentiments are likely to be fuelled by heavy- handed judicial procedures in which large numbers of Uighurs are arrested and processed quickly through a legal system which almost never finds suspects not guilty. Earlier this month, 10 people were arrested for the Urumqi bus bombings. No arrests have yet been made for the Peking blast.

Yining is just across the border from Kazakhstan, the base for the United Revolutionary Front of Eastern Turkestan, an exiled group which claims links with Uighur separatists inside Xinjiang. In the Kazakh capital, Almaty, a spokesman told Reuters news agency that the sentencing would "lead to new spontaneous and massive protest actions. The authorities are merely pushing Uighurs to active revolt". He said a curfew was imposed after the trial.